Speaker 1: Welcome to brain Stuff production of I Heart Radio. Hey
Speaker 1: brain Stuff, Lauren Bogle bom here with a classic episode
Speaker 1: for you today about the strange phenomenon of red snow,
Speaker 1: also called watermelon snow, pink snow, or blood snow. This
Speaker 1: is a phenomenon where snow appears pink to red in
Speaker 1: streaks and patches due to the growth of a species
Speaker 1: of algae, and aside from being visually striking, it's actually
Speaker 1: fairly concerning. Hey brain Stuff, Lauren Bogle bomb here. Normally
Speaker 1: snow looks white. This is because the ice crystals that
Speaker 1: make up clusters of snow reflect and scatter every color
Speaker 1: frequency in the visible light spectrum. So when sunlight bounces
Speaker 1: off of a snow bank, all those colors blend together,
Speaker 1: giving the snow a white appearance, or at least that's
Speaker 1: what usually happens. Every so often, though mother Nature throws
Speaker 1: us a curveball with a blanket of non white snow.
Speaker 1: Plenty of the ld Or was a Roman naturalist who
Speaker 1: lived from twenty three to seventy nine. In one of
Speaker 1: his books, he wrote about red tinted snow, which ancient
Speaker 1: travelers sometimes encountered. His hypothesis was that snow changes color
Speaker 1: as time goes by, like a rusting piece of iron
Speaker 1: snow itself. Plenty wrote Reddens with old age, and reports
Speaker 1: of crimson colored snow kept pouring in over the next
Speaker 1: to millennia. To figure out what's really going on, we
Speaker 1: spoke via email with climate scientist Randall's Serveny. He reports
Speaker 1: people in the dark and Middle Ages were often freaked
Speaker 1: out by it. A professor at Arizona State University, Serveny
Speaker 1: dedicated an entire book to weird weather stories in two
Speaker 1: thousand five, titled Freaks of the Storm. It includes a
Speaker 1: passage on red snow. As Serveny points out, there Charles
Speaker 1: Darwin himself once came across white snow in the Andes
Speaker 1: Mountains that turned blood red as it thawed. Another important
Speaker 1: figure who witnessed the tinted precipitation was Sir John Ross,
Speaker 1: a British naval officer and Arctic explorer. A reddish or
Speaker 1: pinkish snow isn't just a historical curiosit city it's still
Speaker 1: being observed. In February, for instance, a puddle of red
Speaker 1: water that turned out to be melted vermillion snow was
Speaker 1: found in Glacier National Park, So what's the mechanism behind this?
Speaker 1: In some cases, scarlet dust may be a contributing factor.
Speaker 1: Servini said. Many of the historic blood snows of Europe
Speaker 1: are associated with moisture mixing with red Saharan dust that's
Speaker 1: blown northward into Europe, which then falls out as either
Speaker 1: red rain or snow. But it turns out that more
Speaker 1: often than not, red snow is the product of algae,
Speaker 1: and as scientists have learned recently, the stuff is also
Speaker 1: contributing to climate change. We've known for some time now
Speaker 1: that red or pink snow is generally caused by select
Speaker 1: types of green algae, including these species Clematomonas novellis. These
Speaker 1: life forms live in high altitude snow fields around the world.
Speaker 1: Although they're technically green in color, the algae produce a
Speaker 1: red pigment during the warm seasons. Doing so helps protect
Speaker 1: the organisms from excessive solar radiation. We also spoke with
Speaker 1: biologist Arwin Edwards, a research fellow at eberyest With University
Speaker 1: in Wales. He said, I think of the red pigment
Speaker 1: as a sunscreen. He explained the life cycle of this
Speaker 1: and related types of algae. During the winter, the organisms
Speaker 1: go dormant. Once spring arrives, they make their way toward
Speaker 1: the surface of the snow and then bloom. But in
Speaker 1: order to grow, the life forms need liquid water in
Speaker 1: the form of wet snow in order to photosynthesize. This
Speaker 1: is another reason why the red pigment is so useful.
Speaker 1: Dark colored objects absorb more heat than light colored ones.
Speaker 1: In snowy field where clematomotis is present, you'll find dense
Speaker 1: communities of the microorganisms. A single millimeter that's point zero
Speaker 1: three inches of snow can contain five hundred thousand of
Speaker 1: these life forms. So in a large cluster of the
Speaker 1: algae starts to release red pigment and mass, they darken
Speaker 1: the snow they're living in. As a result, the snow
Speaker 1: itself adopts a pinkish look. It also begins to melt.
Speaker 1: So is this a cause for concern? In twice sixteen,
Speaker 1: each tonal Nature published a report written under the leadership
Speaker 1: of Stephanie Lutts, then a scientist at the University of Leeds.
Speaker 1: Edwards was one of her co authors. After looking at
Speaker 1: forty samples of the scarlet material from glaciers in Iceland, Norway,
Speaker 1: Greenland and Sweden, the researchers reached a harrowing conclusion. Edwards said,
Speaker 1: our paper is one of the first of several which
Speaker 1: have identified a five to fiftcent acceleration of glacier melting
Speaker 1: rates as a result of algae on the glacier surface,
Speaker 1: a biological darkening effect. Put another way, glacial snow melts
Speaker 1: five to fifteen percent more rapidly when Clementomonus or similar
Speaker 1: types of algae are present, and that's not good news.
Speaker 1: University of Bristol glaciologist Alejandra Anisio was a co author
Speaker 1: on that Nature paper. Summing up the problem in an
Speaker 1: email exchange, he said, basically, because of the darker coloration
Speaker 1: of snow with the presence of the algae, the snow
Speaker 1: absorbs more of the solar radiation, which increases pretension of
Speaker 1: heat and melting of the snow. The process is not
Speaker 1: in significant and must be taken into account if we
Speaker 1: want to understand how fast glaciers and ice sheets will
Speaker 1: melt with global warming. Also, there may be a self
Speaker 1: perpetuating feedback loop at work here. The red tinted algae
Speaker 1: melts snow, which enables more of the algae to grow,
Speaker 1: which leads to even more melted snow and so on.
Speaker 1: But let's shift gears for a moment and talk about
Speaker 1: one of the red snow's weirdest qualities. It's scent. People
Speaker 1: who come across the algae laden snow sometimes report that
Speaker 1: it has a sweet, watermelon like scent. For the record,
Speaker 1: Edward says he's never detected the odor himself, but that
Speaker 1: it's probably the byproduct of those red pigments. Some popular
Speaker 1: science writers have also advised against eating red snow because
Speaker 1: it has been reported to cause gastric problems, perhaps due
Speaker 1: to the algae other decaying material or mineral dusts and
Speaker 1: snow can come in other colors as well. In January eighteen,
Speaker 1: Central Kazakhstan received a layer of black tinted snow. This
Speaker 1: may have been the result of industrial pollution. Additionally, there
Speaker 1: are some types of algae that create yellowish snow. Of course,
Speaker 1: as any third grader or dog owner can tell you,
Speaker 1: that's not the only way to get yellow snow. Today's
Speaker 1: episode is based on the article the Amazing and Alarming
Speaker 1: science behind red Snow on how stuff Works dot com,
Speaker 1: written by Mark Mancini. Brainstuffs production of My Heart Radio
Speaker 1: in partnership with how Stuff Works dot com and it's
Speaker 1: produced by Tyler Clang. Four more podcasts from My Heart
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